1. Field of the Disclosure
The disclosure is directed to devices and methods for testing and calibrating a subsea multi-phase flow meter during initial well clean-up and test and, in particular, to an adaptor disposed between the subsea Christmas tree and lower riser package to circulate fluid flowing from the subsea Christmas tree, through the subsea multi-phase flow meter, and back into the production bore of the completion/work-over riser.
2. Description of the Related Art
Completion/work-over risers are known in the art. In general, such risers include an emergency disconnect package and a lower riser package and is connected to a surface Christmas tree located on a drilling platform or vessel in offshore completion operations. The surface Christmas tree is in fluid communication with a production bore and an annulus bore which are also in fluid communication with, through the emergency disconnect package and the lower riser package, a subsea Christmas tree connected to a wellhead disposed on the surface of the ocean. Both the production bore and the annulus bore pass through the emergency disconnect package, the lower riser package, and the subsea Christmas tree, each of which includes one or more valves that can be actuated valves or remote operated valves (ROVs).
Connected to the subsea Christmas tree at or near the surface of the ocean, and in fluid communication with at least the production bore passing through the subsea Christmas tree, is a subsea multi-phase flow meter. The subsea multi-phase flow meter is in fluid communication with a production control valve, or choke, which is in fluid communication with a production flow loop hub. During completion, the production flow loop hub is closed off. When the well is ready for production, a flow line is attached to the production flow loop hub to carry fluids from the wellhead through the subsea Christmas tree to a production platform, pipeline, production vessel, and the like.
Before production begins, the wellbore is “cleaned-up” by flowing fluid from the wellbore to which the wellhead is connected, up through the production bore to the drilling platform where it passes through a surface test unit for flow calibration. In flowing up the production bore, the fluid travels a great distance during which the temperature and pressure of the fluid changes. Accordingly, the composition of the fluid changes as a result of these changes in temperature and pressure. Therefore, the testing at the surface is on a different composition of fluid as compared to the fluid flowing through the subsea multi-phase flow meter during production operations. In addition, during this traditional clean-up operation, no fluid flows through the subsea multi-phase flow meter and, therefore, the subsea multi-phase flow meter is not tested for operational integrity, nor is it calibrated before production operations begin.